Rabble-arm and connecting device for central shafts in or-roasters.



No. 727,008. v PATENTED MAY 5, 1903. E. A. 'SJUSTEDT & W. M. GOODWIN.

RABBLE ARM AND CONNECTING DEVICE FOR CENTRAL SHAFTS IN ORE ROASTERS.

APPLIOATION FILED MAE. a, 1902.

N0 MODEL.

UNITED STATES -Patented.May 5, 1903.

PATENT OFFICE.

ERNST A. SJGSTEDT AND WILLIAM MARINER GOODWIN, OF SAULT STE.

MARIE, CANADA, ASSIGNORS TO THE LAKE SUPERIOR POWER COM- PANY, OF SAULT STE. MARIE, CANADA.

RABBLE-ARM AND CONNECTING DEVICE FOR CENTRAL SHAFTS IN ORE-ROASTERS.

SPECTFIGATION forming part of Letters Patent No. 727,008, dated. May 5, 1903.

Application filed March 8, 1902. Serial No. 97,358. (No model.)

To all whom it may concern:

- Beitknown thatwe,ERNsTADoLF SJosTED'r and WILLIAM MARINE-R GOODWIN, of Sault Ste. Mario, in the district of Algoma, in the Province of Ontario, Canada, have invented certain new and useful Improvements in Rabble-Arms and Connecting Devices to (Jentral Shafts in Ore-Roasters; and we do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part hereof.

Our invention, which will be hereinafter fully set forth and claimed, relates to the construction of rabble arms or stirrers and the mode of securing them removably to the central hollow shaft of ore-roasting furnaces.

The object of our invention is a rabble-arm of more approved cross-section and especially of a more secure mode of securing the same to the central hollow shaft.

Figure l is a horizontal section of the central shaft on the lines 1 1 and 1 1, Fig. 2. Fig. 2 is an elevation of part of the central shaft, showing the socket or mortise for the rabble-arm. Fig. 3 is a vertical transverse section on line 3 3, Fig. 1, showing the socket or mortise on one side and the other half being in elevation. Fig. 4 is a top view of the rear end of the rabble-arm. Fig. 5 is an elevation of the same, and-Fig. 6 isan end view of the same.

The rabble-arm A is of circular tubular cross-section, tapering from the rear end to the free end and having on its lower surface the teeth e. The rear end a, intended to enter the central hollow shaft, is tapered rearwardly to form a taper plug or tenon. This I tenon is provided with lugs ct on opposite mouth of said sockets or mortises are formed grooves 11, registering with the lugs a on the tenons of the arm when the arms are turned approximately a quarter of a turn.

These grooves b are short and are continued-inside the socket at a right angle for about a quarter of a turn, forming an annular recess if within the socket.

If a rabble-arm is to be inserted, the end of the tenon a is inserted into the mouth of the socket b and turned out of its way until the lugs a register with the grooves b. The arm is then pushed home and twisted into its position, whereby the lugs a travel in the annular grooves b rest there, and are thus locked into position, it beingimpossible to withdraw the arm without turning it back, so that the lugs stand opposite the grooves b.

If an arm is to be replaced, all that is necessary is to twist the arm until the lugs a register with the grooves Z2, when the arm may be freely withdrawn.

The arrow, Fig. 1, shows the direction in which the central shaft B rotates. The recesses b are made in a direction from the grooves b opposite to that of the direction of rotation of the hollow shaft, so that the arm when being inserted has to be turned in the same direction in which it would be turned by the resistance of the teeth e in the ore on the hearth. The resistance of the lugs a against the shoulders of the recesses 21 keeps the arm in the desired position when once insorted.

It will be observed that on account of the arm being only required to be turned on its own axis when being inserted or removed a very small opening in the casing of the furnace is required for that purpose, also that the arm is firmly seated and no lifting action which might be caused in the ore in which the teeth 6 are working will dislocate it.

We claim as our invention 1." The combination in a roasting-furnace of a hollow vertical shaft having a mortise or socket circular in cross-section and tapering lengthwise and having short longitudinal grooves in its rim or month saidgrooves being continued within the socket at a right angle and stopped to form recesses, of a rabble-arm having a conical plug fitting the said socket in the vertical shaft and said plug having lugs registering with the said grooves and I turned at a right angle and continued for a fittingthe said recesses, substantially as set quarter of a turn and stopped, substantially forth. I as set forth.

2. The combination of a hollow rabble-arm In testimony whereof we have signed in the 15 5 with teeth and havinga circular tapering pl ng presence of the undersigned witnesses.

end with shouldered lu snear the thick end, H

a hollow shaft having transverse open sockets Y 1 1 I l MARIMJR (1001mm circular in cross-section and tapering lengthwise to fit the plug ends of the arms, said Witnesses: xo sockets each provided with grooves at the FRANK E. LEAOH,

month and said grooves inside said sockets XV. A. BARTHOLOMEW. 

